1. Field of the Invention
The present invention relates to detection systems with receptors controlled by an emitter and comprising an electronic control center some of whose nodes are adapted to direct a control circuit and whose at least one node P.sub.i is connected to the receptor which may take, thanks to a supply source V.sub.cc, either a conducting state when it is correctly influenced by the emitter and for which the node P.sub.i is brought to an active state permitting the control center to direct the control circuit, or in a non-conducting state when it is incorrectly influenced by the emitter and for which the node P.sub.i is brought to an inactive state preventing the control center from directing said control circuit.
2. Description of the Related Art
Such detection systems, in which the receptor may be a HALL effect cell, or an infrared receptor or an oscillating coil, are generally utilized to control security devices, or to direct control circuits of electric devices according to the presence or absence of the emitter; for example, a HALL effect receptor has already been utilized in culinary robots with multiple functions. In either of these uses, the functioning of the detection system relies entirely on the dependability of the receptor.
Unfortunately, it happens that in certain cases, these components present anomalies at the level of the HALL effect cell, or of the infrared cell, and/or the output transistor and assume their conducting state permanently, without regard to the influence of the emitter. The detection system therefore becomes ineffectual in all of its applications and particularly in those of security and may even, when utilized in an electric device such as a culinary robot, occasion injury to the user who is confused as to the functioning of the device.
The goal of the invention is therefore to eliminate these disadvantages and to render the functioning of these detection systems dependable.
According to the invention, the detection system comprises a device to verify the proper functioning of the receptor which comprises an additional control circuit connected, on the one hand, to the receptor, and, on the other hand, to another node P.sub.c of the control center, as well as in the control center a generator-programmer which controls, at intervals, the emission on said node P.sub.c of a signal activating the additional control circuit forcing the receptor to assume its non-conducting state, and which analyzes the instantaneous state corresponding to the node P.sub.i as a function of the state of the node P.sub.c in such a manner as to prevent the control center from directing the control circuit if this instantaneous state is different from the inactive state.
Thanks to this verification device, one is certain that whatever the state of functioning of the receptor, damaged or not, the control center will not be able to direct the control circuit, even in the presence of the emitter or of the object to be detected, as long as the comparison made at time intervals determines the incompatibility between the activation signal on the node P.sub.c and the state of the node P.sub.i subordinated to the receptor which must assume, under this activation, its non-conducting state.